2007 Apr: Two-point Problem of the Rate of Change

[eSignal_JasonK]

File Name: Adjusted_ROC.efs

Description:
This study is based on the April 2007 article, Two-Point Problem of the Rate of Change, by Martti Luoma and Jussi Nikkinen.

Formula Parameters:
Periods: 21


Notes:
The related article is copyrighted material. If you are not a subscriber of Stocks & Commodities, please visit www.traders.com.


Download File:
Adjusted_ROC.efs



EFS Code:

/***************************************
Provided By : eSignal (c) Copyright 2007
Description:  Two-Point Problem of the Rate of Change 
              by Martti Luoma and Jussi Nikkinen

Version 1.0  2/05/2007

Notes:
* April 2007 Issue of Stocks and Commodities Magazine
* Study requires version 8.0 or later.


Formula Parameters:                     Default:
Periods                                 21
*****************************************************************/

function preMain() {
    setStudyTitle("Adjusted ROC ");
    setCursorLabelName("AdjROC", 0);
    setDefaultBarFgColor(Color.red, 0);
    setDefaultBarThickness(2, 0);
    

    var fp1 = new FunctionParameter("Periods", FunctionParameter.NUMBER);
        fp1.setName("Periods");
        fp1.setLowerLimit(1);
        fp1.setDefault(21);
}

// Global Variables
var bVersion  = null;    // Version flag
var bInit     = false;   // Initialization flag
var xAdjROC   = null;



function main(Periods) {
    if (bVersion == null) bVersion = verify();
    if (bVersion == false) return;    

    //Initialization
    if (bInit == false) {
        xAdjROC = efsInternal("calcAdjROC", Periods);
        bInit = true;
    }

    
    return xAdjROC.getValue(0);
}


// AdjROC globals
var xEMA = null;

function calcAdjROC(nP) {
    if (bInit == false) {
        xEMA = ema(nP, roc(1));
        bInit = true;
    }
    
    var nEMA = xEMA.getValue(0);
    if (nEMA == null) return;
    
    return (nEMA * nP);
}


function verify() {
    var b = false;
    if (getBuildNumber() < 779) {
        drawTextAbsolute(5, 35, "This study requires version 8.0 or later.", 
            Color.white, Color.blue, Text.RELATIVETOBOTTOM|Text.RELATIVETOLEFT|Text.BOLD|Text.LEFT,
            null, 13, "error");
        drawTextAbsolute(5, 20, "Click HERE to upgrade.@URL=http://www.esignal.com/download/default.asp", 
            Color.white, Color.blue, Text.RELATIVETOBOTTOM|Text.RELATIVETOLEFT|Text.BOLD|Text.LEFT,
            null, 13, "upgrade");
        return b;
    } else {
        b = true;
    }
    
    return b;
}